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Can weight-strengthening exercises reduce mortality risk? Cavan Images/Getty Images
  • The authors of a new meta-analysis of prior studies wanted to determine how much time adults should spend doing muscle-strengthening exercises each week.
  • They conclude that doing 30–60 minutes of these exercises each week lowers the risk of all-cause death, cardiovascular disease, and cancer.
  • They also report that up to 1 hour of muscle-strengthening exercises a week reduces the risk of developing diabetes.
  • However, limitations in the data mean that more research is necessary to clarify the results.

Although the health benefits of aerobic exercise are well-established, there has been less research into the health benefits of muscle-strengthening exercises.

Recently, a group of researchers from Japan set out to investigate.

The study, which appears in the British Journal of Sports Medicine, took data from existing studies to learn more about how these exercises affect health.

The findings showed that adults who do 30–60 minutes of muscle-strengthening exercises each week have a 10–20% reduction in mortality risk, alongside a reduced risk of other health conditions.

Being physically active is important for maintaining good physical and mental health.

The Department of Health and Human Services (HHS) recommends that adults participate in 150–300 minutes of moderate intensity or 75–150 minutes of vigorous intensity aerobic physical activity each week to ensure “substantial health benefits.”

Aerobic exercises improve heart health. Some examples include swimming, cycling, walking, and rowing.

Additionally, the HHS recommends that adults do muscle-strengthening exercises on 2 days of each week. Some types of exercises that strengthen the muscles include weightlifting, using resistance bands, and doing bodyweight exercises, such as pushups, situps, and squats.

The HHS notes that “nearly 80% of adults are not meeting the key guidelines for both aerobic and muscle-strengthening activity.”

The goal of this study was to use previously published research to determine how much time adults should spend per week doing muscle-strengthening exercises to improve overall health.

The researchers used data from 16 relevant observational studies published between 2012 and 2020 to determine the health benefits of these exercises. They focused on studies with participants who did not have any major health issues.

Each study that the authors reviewed had data from thousands of participants, and one of the studies included data from almost 480,000 people. The included studies followed the participants for a minimum of 2 years.

According to the authors, “All studies focused on muscle-strengthening exercises such as resistance/strength/weight training and calisthenics, but not on muscle-strengthening activities such as carrying heavy loads and heavy gardening.”

After analyzing the data, the authors determined that muscle-strengthening activities were associated with a 10–17% lower risk of all-cause mortality. There was also a similar risk reduction for cardiovascular disease, diabetes, total cancer, and lung cancer.

While there were reductions in overall cancer and lung cancer cases, the researchers did not find a risk reduction for other cancers, such as colon, kidney, bladder, and pancreatic cancer.

Dr. Anton Bilchik spoke with Medical News Today about the study findings. Dr. Bilchik is a surgical oncologist, professor of surgery, chief of medicine, and director of the gastrointestinal research program at Saint John’s Cancer Institute in Santa Monica, CA.

“This study is important because it is a meta-analysis of 16 prospective cohort studies that demonstrates that muscle-strengthening activity reduces the risk of developing cardiovascular disease, cancer, and diabetes,” said Dr. Bilchik.

“The maximum risk reduction was 10–20% if 60 minutes [each] week of muscle-strengthening was performed. There was, however, no association with specific cancers, such as colon, kidney, bladder, and pancreas.”

Dr. Bilchik also explained why muscle-strengthening exercises can be so beneficial:

“The authors suggest that muscle strengthening is associated with preservation of skeletal muscle mass, which then plays an important role in glucose metabolism. Abnormal glucose metabolism has been associated with an increase in cardiovascular disease and cancer.”

Although the authors found that doing 30–60 minutes of muscle-strengthening exercises each week provided health benefits, they did not find evidence that going beyond 60 minutes provided additional benefits.

Even though the researchers had access to additional studies, they do acknowledge the need for more research.

“Given that the available data are limited, further studies — such as studies focusing on a more diverse population — are needed to increase the certainty of the evidence,” write the authors.

Dr. Steve Vasilev also spoke with MNT about the study. Dr. Vasilev is a quadruple board certified integrative gynecologic oncologist and medical director of integrative gynecologic oncology at Providence Saint John’s Health Center. He is also a professor at Saint John’s Cancer Institute.

“As this systematic review states, muscle-strengthening exercise’s influence on noncommunicable diseases such as cancer and heart disease has been studied less than the influence of aerobic exercise on the same groups,” commented Dr. Vasilev.

“While there were a few highlights that suggest a favorable effect, especially when combined with aerobic exercise, the relative risk reduction of incidence and mortality was generally small, and the quality of evidence for all of these papers combined was noted to be low to very low,” Dr. Vasilev continued.

“This functionally makes this data almost uninterpretable. Having said that, I applaud the effort in trying to show that lifestyle modification can favorably influence prevention and the course of diseases such as cancer and heart disease.”